a.Before lighting the unit for the ®rst time, perform the following: If the gas supply pipe was not purged be- fore connecting the unit, it will be full of air. It is rec- ommended that the ground joint union be loosened, and the supply line be allowed to purge until the odor of gas is detected. Never purge gas lines into a com- bustion chamber. Immediately upon detection of gas odor, retighten the union. Allow 5 minutes to elapse, then light unit.
b.Make sure that
c.Make sure that air ®lter(s) is in place.
d.Make sure that condensate drain trap is ®lled with wa- ter to ensure proper drainage.
e.Make sure that all tools and miscellaneous loose parts have been removed.
Fig. 23 Ð Fan Blade Clearance
START-UP
Check for Refrigerant Leaks Ð Proceed as follows to locate and repair a refrigerant leak and to charge the unit:
1.Locate leak and make sure that refrigerant system pres- sure has been relieved and reclaimed from both high- and
2.Repair leak following accepted practices.
NOTE: Install a ®lter drier whenever the system has been opened for repair.
3.Add a small charge of
4.Evacuate and reclaim refrigerant from refrigerant system if additional leaks are not found.
5.Charge unit with
Start Up Heating Section and Make Adjustments
Complete the required procedures given in
Do not jumper any safety devices when operating the unit.
Make sure that burner ori®ces are properly aligned. Un- stable operation may occur when the burner ori®ces in the manifold are misaligned.
Follow the lighting instructions on the heating section operation label (located inside the burner or blower access door) to start the heating section.
NOTE: Make sure that gas supply has been purged, and that all gas piping has been checked for leaks.
CHECK HEATING CONTROL Ð Start and check the unit for proper heating control operation as follows. (See furnace lighting instructions located inside burner or blower access panel.)
1.Place the room thermostat SYSTEM switch in the HEAT position and the fan switch in the AUTO. position.
2.Set the heating temperature control of the thermostat above room temperature.
3.The
4.After a call for heating, the main burner should light with- in 5 seconds. If the burners do not light, there is a
5.The evaporator fan will turn on 45 seconds after the flame has been established. The evaporator fan will turn off 45 seconds after the thermostat has been satis®ed.
CHECK GAS INPUT Ð Check gas input and manifold pres- sure after unit
The rated gas inputs shown in Table 5 are for al- titudes from sea level to 2000 ft above sea level. These in- puts are based on natural gas with a heating value of 1050 Btu/ft3 at 0.65 speci®c gravity, or propane gas with a heating value of 2500 Btu/ft3 at 1.5 speci®c gravity. For elevations above 2000 ft, reduce input 4% for each 1000 ft above sea level. When the gas supply being used has a different heating value or speci®c gravity, refer to national and local codes, or contact your distributor to determine the required ori®ce size.
These units are designed to consume the rated gas in- puts using the ®xed ori®ces at speci®ed manifold pres- sures as shown in Table 5. DO NOT REDRILL THE ORIFICES UNDER ANY CIRCUMSTANCES.
ADJUST GAS INPUT Ð The gas input to the unit is determined by measuring the gas ¯ow at the meter or by measuring the manifold pressure. Measuring the gas ¯ow at the meter is recommended for natural gas units. The mani- fold pressure must be measured to determine the input of propane gas units.
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